Three-Wheeled Vehicle With Multipart Frame

ABSTRACT

A vehicle, such as a cargo bike, may include a multipart frame, a single wheel, and a wheel pair which comprises two mutually spaced wheels, where the single wheel is connected to a first frame part of the frame, and the two wheels of the wheel pair are rotatably mounted on a second frame part of the frame about a common axis. The first frame part and the second frame part may be connected by at least one joint and can be rotated relative to each other about a pivot axis defined by the at least one joint, and the pivot axis may run through a contact point of the single wheel.

BACKGROUND AND SUMMARY

The invention relates to a three-wheeled vehicle, in particular a cargobike, which has a multi-part frame, in particular a frame divided intotwo, the frame parts thereof being connected by at least one joint, andthe at least one joint thereof defining a pivot axis about which theframe parts are pivotable relative to one another, or mutuallypivotable, respectively.

Cargo bikes nowadays, and against the background of new concepts andsolutions for individual mobility being required, are becoming ever morepopular. Therefore, a multiplicity of implementations relating to thesecargo bikes and to three-wheeled vehicles in general are already knownin the prior art.

For example, there are two-wheeled and three-wheeled cargo bikes,wherein in the case of three-wheeled cargo bikes a pair of wheels havingtwo wheels may be disposed at the front or the rear. Such cargo bikes,or generally such three-wheeled vehicles, include not only purelypedal-driven bikes but likewise e-bikes which support the mechanicaldrive by an electric drive, but also other three-wheeled vehicles whichare exclusively motor-driven, for example.

However, cargo bikes, bicycles or e-bikes having a plurality of wheelsare typically long, heavy and difficult to steer. In particular when aload is additionally being carried it may arise that this load, as amoving mass, acts on the vehicle and counteracts the steering movements,which may lead to critical or even dangerous and uncontrollable steeringmaneuvers and thus to accidents.

Apart from the difficult steering, the frame can be set in vibration bythe moving mass during load reversals, which over time can bedetrimental to the stiffness and stability of the frame such that theframe may break.

It follows from this disadvantageous behavior, which is unexpected formany drivers, that the cargo bikes, or three-wheeled vehicles,respectively, that are known in the prior art cannot be intuitivelyoperated by drivers who are used to a customary bicycle. Accordingly,many drivers require some initial familiarization and training beforethe cargo bikes can be safely driven, or before the cargo bikes are tobe driven in traffic.

In the case of bicycles having two wheels, or a pair of wheels, at thefront, complex axle steering is required in some instances. Variants ofcargo bikes having two wheels, or a pair of wheels, at the rear, such asconventional rikshaws, for example, are often of a rigid embodiment suchthat the frame of the bicycle cannot lean into the curve.

However, there are also variants of three-wheeled vehicles in which theentire frame, or at least part thereof, and in particular the front partof the frame, is laterally pivotable and, as a result, can lean into thecurve when cornering, this being fundamentally intended to enable a moreergonomic and more dynamic driving style and also corresponding to thebehavior of a “normal” bicycle.

Such vehicles, having an at least partially pivotable frame, are knownfrom documents DE 10 2014 113 710 A1, DE 10 2016 115 803 A1, EP 3 205564 B1, DE 10 2016 120 697 B4, FR 3 020 335 B1, JP 5995434 B2, KR10-1197628, US 3 605 929 A, US 6 104 154 A, and WO 2011/107674 A1, forexample, which are each hereby incorporated by reference in theirentireties.

However, the pivoting in the known solutions, as a result of therespective superstructure, leads to lateral forces potentially engagingon the front wheel when leaning into the curve, the front wheel by theseforces being steered out its track such that the front wheel is offsetin relation to its previous track relative to the pair of wheels on therear axle (the rear wheels), this having a negative effect on thesteering behavior.

Moreover, a lever action as a result of the pivoting is often generatedon the front wheel, as a result of which the latter is pushed downwardwhile negotiating curves, this increasing the probability of the frame,or the pivotable front part of the frame, tilting. This lever action, orthe force caused by the lever action, respectively, is moreoverdependent on the payload such that the behavior of the vehicle can varyheavily as a function of the payload, or as a function of the movingmasses, respectively, this adding to the unpredictability of thevehicle.

Therefore, in at least one aspect, the invention is based on the objectof overcoming the aforementioned disadvantages and of providing athree-wheeled vehicle which has a driving behavior similar to that of aconventional bicycle and makes it possible to lean into curves.

This object is achieved by the combination of features according to theclaims.

Proposed according to the invention is a vehicle, in particular a cargobike, which has a multi-part frame, preferably a two-part frame, asingle wheel, and a pair of wheels. Apart from a cargo bike which isoperated purely by muscular power, inter alia three-wheeled e-bikes,purely electrically driven three-wheeled vehicles or hybrid solutionsare also understood to be such a vehicle which is three-wheeled onaccount of the single wheel and the pair of wheels. A single wheel is inparticular understood to be a singular wheel, wherein a plurality ofwheels that substantially act as one wheel may also represent a singlewheel, this being the case, for example, when these wheels are embodiedas a twin wheel, or the spacing between the wheel or tire contact faces,respectively, is very minor and below 5 cm, for example. The pair ofwheels has in particular two wheels which are mutually spaced apart in atransverse direction of the vehicle. The single wheel is connected to afirst frame part of the multi-part frame, and the two wheels of the pairof wheels are mounted on a second frame part of the frame so as to berotatable about a common axis. The connection between the single wheeland the first frame part is preferably embodied by way of anintermediate element, such as a wheel fork, for example, such that thesingle wheel, in particular as the front wheel, is fixed to the firstframe part with the wheel fork and with the latter is pivotable about asteering axis. Accordingly, the single wheel is assigned to the firstframe part, and the pair of wheels is assigned to the second frame part.It is furthermore provided that the first frame part and the secondframe part are connected by at least one joint and are mutuallyrotatable, or able to be twisted or pivoted, respectively, about a pivotaxis defined by the at least one joint, such that the first frame partcan thus be moved relative to the second frame part about the pivotaxis. According to the invention, the pivot axis runs through a contactpoint of the single wheel. Since wheels in an ideal case, which at bestis absent in reality, contact a hard surface or the carriageway only ata single one-dimensional point, the contact point, which may also bereferred to as the wheel contact point, is not understood to be only aone-dimensional point but rather also the contact area, or an idealizedcontact point of the single wheel within the contact area, on acarriageway or a hard surface.

As a result of the pivot axis running through the contact point, arotation of the single wheel during pivoting of the frame parts takesplace about the contact point such that no track offset and no leveragearise. As a result, riding without holding the handlebars is alsopossible, for example. As a result of the rear structure, or the rear orsecond frame part, respectively, being decoupled from the pivot axis,the weight of a load bearing on the second frame part is neither steerednor does the latter lean into the curve, so that these masses do not actas a moving mass and have no negative effect on the behavior of thefront or first frame part, or the driving behavior of the vehicle,respectively.

The pivot axis preferably runs in a symmetry plane of the vehicle, or ina symmetry plane of the frame, or at least of the first frame part,respectively.

As has been mentioned above, the single wheel is preferably a frontwheel which on a wheel fork is connected to the first frame part so asto be pivotable about a steering axis. Accordingly, the wheels of thepair of wheels form the rear wheels of the vehicle. Since the contactpoint forms the lowest point of the single wheel, or front wheel,respectively, the pivot axis, proceeding from the rear of the vehicle,slopes downward in the direction of the front wheel.

One advantageous refinement provides that the first frame part and thesecond frame part are connected by at least two joints which aredisposed so as to be mutually spaced apart on the pivot axis. While theframe parts are preferably connected exclusively by the joints, and/ordevices for the transmission of torque or control devices, such aschains, brake cables, electrical lines or the like, for example, canextend between the frame parts. A first joint of the two joints is aball joint, a radial bearing or an elastomer element which is inparticular flexible and reversibly deformable. Furthermore, a second joint of the two joints is a ball j oint, a radial bearing or anelastomer element which is likewise in particular flexible andreversibly deformable. This gives rise to various advantageouscombinations. For example, the first and indeed the second joint can ineach case be a ball joint, in each case be a radial bearing, or in eachcase be an elastomer element, wherein hybrid forms in which the firstjoint is an elastomer element and the second joint is a ball joint, forexample, are also possible. Elastomer elements moreover have theadvantage that the latter not only permit pivoting but at the same timealso absorb impacts and shocks and transmit the latter less intensely tothe vehicle frame.

In order for the profile of the pivot axis to be able to be adjusted,for example when replacing the wheel of the single wheel or in any othersituation that displaces the contact point in relation to the pivotaxis, in one particularly advantageous refinement the position of thefirst joint and/or of the second joint in relation to the first framepart and/or the second frame part is adjustable. The position, or therespective position, of the joint is preferably adjustable in thehorizontal direction, or in the height direction in terms of thevehicle, and/or in the vertical direction or in the longitudinaldirection in terms of the vehicle, respectively, such that, as a resultof a corresponding adjustability of the position, or as a result of acorresponding displacement capability of the joints, respectively, thepivot axis can be displaced or rotated to a profile that intersects thecontact point.

As an alternative to an embodiment which has two, or at least two,joints, a variant in which the first frame part and the second framepart are connected by exactly one joint formed by at least one radialbearing is likewise advantageous. While a plurality of radial bearingsand/or axial bearings may be disposed in the preferably exactly onejoint, the latter is distinguished in that the joint forms a single andpreferably encapsulated module. As a result, the bearings of the jointare comparatively close to one another such that the forces cannot beabsorbed in an optimal manner, but other advantages such as, forexample, improved protection in relation to contamination, a morecompact construction and simplified assembling are indeed derived owingto the improved encapsulation.

In order to be able to adjust the angle in the case of a single jointthat permits pivoting about the pivot axis, and as a result to be ableto adjust the profile of the pivot axis through the contact point, it isfurthermore preferably provided that the angle of the single joint isadjustable in relation to the first frame part and/or the second framepart, the joint per se or the joint by a corresponding device thus beingconfigured to be twisted about a transverse axis of the vehicle.

In order to prevent the vehicle or the first frame part from fallingover when stationary, or to prevent a dangerous inclination of the firstframe part in relation to the second frame part during travel, a furtherdesign embodiment provides that the vehicle furthermore comprises adelimiting device which is configured to restrict a rotatability of thefirst frame part in relation to the second frame part about the pivotaxis, or to restrict the rotatability to a pre-defined angular range.Such a delimiting device can be, for example, also a simple stand whichcan be folded out when the vehicle is stationary and supports the firstframe part in relation to the ground. Alternatively, a fixing devicewhich when the vehicle is stationary can be disposed so as to rigidlyconnect the first frame part to the second frame part such that theframe parts can no longer rotate or pivot in relation to one anotherwhen stationary, can likewise be considered. Apart from such deviceswhich are suitable only for the stationary vehicle, further alternativeswhich restrict a rotatability of the joints and as a result alsorestrict pivoting of the frame parts can also be considered.

A further alternative design embodiment provides that the vehiclefurthermore comprises a restoring device which is configured to rotateor pivot the first frame part, from a position deflected in relation toa pre-defined central position, back to the central position. Thecentral position here preferably corresponds to a resting position inwhich the first frame part and the second frame part are situated whentraveling straight ahead without a steering input, or are in each casecompletely upright, respectively. Such a restoring device can beimplemented by springs, for example, or else gas struts. In particularwhen an elastomer element is provided as one of the joints, theelastomer element can integrally form the delimiting device and/or therestoring device. Moreover, such a restoring device can complement orentirely replace a delimiting device, because the restoring devicegenerates a restoring moment by way of which the frame, or the frameparts, respectively, are mutually aligned even when stationary.

The vehicle furthermore preferably has at least one drive device whichgenerates a torque and is a motor, for example, or a pedal mechanismwhich is operated by muscular force. The drive device is disposed on thefirst frame part or directly on the single wheel and is configured totransmit the torque to the single wheel. Alternatively, the drive deviceis disposed on the second frame part or directly on one of the wheels ofthe pair of wheels and configured to transmit the torque to at least oneof the wheels of the pair of wheels. Accordingly, the variants providethat the transmission of torque from the drive device to the respectivedriven wheel or the respective driven pair of wheels does not take placeby way of the separating plane between the frame parts but directly inthe region of one of the frame parts. Such a drive device can moreoveralso be provided as a wheel hub motor, for example, so that the drivedevice can also be disposed directly in a wheel hub of the single wheelor in one of the wheels of the pair of wheels, for example. If the rearwheels, or the wheels of the pair of wheels, respectively, are to bedriven, the drive device can be configured as a central rear ormid-mounted motor, wherein the torque between the wheels of the pair ofwheels can be split and controlled by way of a torque-splitting device(torque vectoring).

Additionally or alternatively, the vehicle may furthermore have at leastone optional second drive device which generates a torque and in turncan be a motor or else a device for driving by muscular force. The drivedevice is disposed on the first frame part and is configured to transmitthe torque to at least one of the wheels of the pair of wheels by way ofa torque transmission device. Alternatively, the drive device isdisposed on the second frame part and configured to transmit a torque tothe single wheel by way of the torque transmission device. In thisvariant, it is thus provided that the transmission of torque by thecorresponding device takes place across the separating plane between theframe parts, wherein the torque transmission device is preferablyconfigured to permit pivoting or twisting of the frame parts about thepivot axis without being damaged, respectively.

A further variant provides that one drive device drives the single wheelas well as at least one of the wheels of the pair of wheels, wherein thetransmission of torque in this instance takes place with at least onedevice suitable for this purpose.

The vehicle can also be provided with a serial hybrid drive in which agenerator driven by muscular force generates current, for example, whichwith corresponding lines is transmitted across the separating planebetween the frame parts to an electric drive device, the latter drivingat least one of the wheels.

The torque transmission device in a particularly advantageous variant isa prop shaft which, at least in the region of a dividing plane betweenthe first frame part and the second frame part that is defined by the atleast one joint, extends from the first frame part to the second framepart so as to be coaxial with the pivot axis. Since the prop shaft isthus coaxial with the pivot axis, the prop shaft remains substantiallyunaffected by the mutual pivoting of the frame parts. For example, if asingle joint is provided, the prop shaft can extend through the joint.

Apart from a classic, rigid prop shaft, which is distinguished inparticular by universal joints, a flexible or elastic shaft may also beused as an alternative.

Alternatively, the torque transmission device, in the case of a likewiseadvantageous configuration, is a chain drive which has a chain and ofwhich the chain permits and compensates a twisting about the pivot axis,or of which the chain is configured to permit and compensate a twistingabout the pivot axis at least within a pre-defined range, respectively.For this purpose, a chain guide and/or a chain tensioner, by way ofwhich it is ensured that the chain does not jump from the associatedsprockets while the frame parts are pivoted, can preferably be provided.

For example, the mechanical transmission of force, or the transmissionof torque, respectively, can take place in a manner optimized in termsof force, and in a simple and cost-effective manner by means of abicycle chain which enables torsion between a front chainring on thefirst frame part and a rear sprocket on the second frame part of atleast 45°, and has to be guided in each case only at the top and thebottom on the front chainring and on the rear sprocket in order toprevent the chain from jumping off.

The features disclosed above can be combined in any suitable manner tothe extent that this is technically possible and the features are notmutually contradictory.

BRIEF DESCRIPTION OF THE FIGURES

Other advantageous refinements of the invention are illustrated in moredetail in the claims and specification, including hereunder inconjunction with the description of the preferred embodiment of theinvention by means of the figures. In the figures:

FIGS. 1 a, 1 b show a first vehicle variant in a lateral view and a planview from above;

FIGS. 2 a, 2 b show a second vehicle variant in a lateral view and aplan view from above;

FIGS. 3 a, 3 b show a third vehicle variant in a lateral view and a planview from above;

FIG. 4 a shows a view of a single wheel in the central position anddeflected positions of a vehicle variant according to the invention;

FIG. 4 b shows a view of a single wheel in the central position anddeflected positions of a vehicle of the prior art;

FIGS. 5 a-e show in each case a drive configuration of a vehiclevariant.

The figures are schematic in an exemplary manner. The same referencesigns in the figures refer to identical or similar functional and/orstructural features.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 a to 3 b show in total three variants of a vehicle 1, in eachcase in a lateral view and in a plan view from above.

The vehicle variants use in each case dissimilar joints 21, 22, 23 inorder to configure a pivot axis X about which a first frame part 14 ispivotable in relation to a second frame part 15 of a vehicle frame,wherein the pivot axis X runs in each case through a contact point A ofthe single wheel 11 configured as the front wheel on or with the groundB, respectively.

Since the joint 23, or the joints 21, 22, is/are in each case disposedin a rear region, or on a rear region of the vehicle 1, respectively,and define a separating or dividing plane between the first, or thefront, frame part 14 and the second, or the rear, frame part 15,respectively, this results in a profile of the pivot axis X that slopesdownward from the rear toward the front and intersects the contact pointA of the single wheel 11.

For the sake of improved orientation in the figures, a coordinate systemor axis system, respectively, which identifies the respective axes isillustrated both in FIGS. 1 a to 3 b and in FIGS. 4 a to 5 e . Thecoordinate system, which refers to the vehicle, defines the longitudinalaxis L of the vehicle, the height axis H of the vehicle, and thetransverse axis Q of the vehicle.

Since a cargo bike is in each case illustrated as an exemplaryembodiment of a vehicle 1 according to the the embodiments of FIGS. 1 ato 3 b , the front wheel, or the single wheel 11, respectively, ismounted in each case on a wheel fork 16 and by way of the wheel fork 16is connected to the first or the front frame part 14 so as to berotatable about a steering axis. For the sake of simplification, thewheel fork 16 can be considered to be part of the first frame part 14.

A pedal drive or pedal mechanism, as is also known from conventionalbicycles, is in each case provided as the drive device 31 for drivingthe vehicle 1 in FIGS. 1 a to 3 b . Accordingly, a gearshift can also beprovided, for example. Provided for transmitting a torque from the drivedevice 31, which is operated by muscular force, to at least one of thewheels 11, 12, 13 is presently a torque transmission device 34 which isconfigured as a chain drive or chain gear, respectively, such that thetorque from the drive device 31 is thus transferred to an axle whichruns between the wheels 12, 13 of the pair of wheels by means of a chainrunning via sprockets, the rear wheels, thus the wheels 12, 13 of thepair of wheels, being equally driven by the axle in the examplesillustrated in FIGS. 1 a to 3 b .

Since a chain which spans the dividing plane between the frame parts 14,15 is provided in the variants according to FIGS. 1 a to 2 b , a chaintensioner is furthermore shown in the figures, by way of which apre-defined or adequate chain tension is maintained even when the chainis torsioned while tilting the frame parts 14, 15. Moreover, a guideinstallation for guiding the chain can preferably be provided.

This is only an exemplary drive configuration, wherein furtherconfigurations are possible, for example according to FIGS. 5 a to 5 e .

It is furthermore to be established that the rear, or the second framepart 15, respectively, in the variants shown in FIGS. 1 a to 3 b , andmoreover also in the embodiment according to FIG. 5 e , is configured asan integral, substantially rectangular structure (in the plan view fromabove) which is configured as the load carrier, on which the loads whichare to be transported by the cargo bike can thus be disposed directly,or for example by way of a receptacle (not illustrated) such as aplatform, a basket or seats, on the second frame part 15.

In the variant according to FIGS. 1 a and 1 b the pivotability, orrotatability, respectively, of the front or first frame part 14 inrelation to the rear or second frame part 15, the latter being supportedin relation to the ground by way of the wheels 12, 13 that are spacedapart in the transverse direction Q of the vehicle, is implemented bytwo single joints 21, 22 which are mutually spaced apart along the pivotaxis X. The further the single joints 21, 22 are spaced apart along thepivot axis X, the better the forces acting between the frame parts 14,15 can be absorbed. To this end, even further single joints may beprovided. The two single joints 21, 22 presently are configured as aball joint or a ball head joint, respectively, which have been known fora long time in the prior art and the construction of which therefore isnot to be described in more detail. In terms of these joints it is onlypointed out that a joint head of the ball joint is connected in asubstantially rigid manner to one of the frame parts 14, 15, and that ajoint socket, in which the joint head is mounted so as to be rotatablein multiple axes, is connected in a substantially rigid manner to therespective other frame part 14, 15. As a result of at least two suchjoints 21, 22 which are configured as a ball joint, the degrees offreedom of the joints are restricted to a rotatability about the pivotaxis X.

Deviating therefrom, the variant according to FIGS. 2 a and 2 b does notprovide two single joints 21, 22 but provides exclusively a single joint23 which can be formed by an elongate radial bearing or joint,respectively, or else by a plurality of radial bearings or joints,respectively, that are encapsulated in a module. In comparison to theembodiment of FIGS. 1 a and 1 b , this results in an improvedencapsulation of the joint 23 such that the latter can be more easilyinstalled and is better protected in relation to contamination. However,this in most instances results in a distance for absorbing the forceswhich is smaller in comparison to the distance which in the variantaccording to FIGS. 1 a and 1 b absorbs the forces between the frameparts 14, 15, the distance in the vehicle 1 in FIGS. 2 a and 2 bcorresponding to the length of the single joint 23 along the pivot axisX.

It is also advantageous in the variants according to FIGS. 1 a to 2 bthat a bicycle saddle and the drive device 31 are disposed on the frontor first frame part 14 and, as a result, lean into curves when the firstframe part 14, having a driver sitting on the vehicle 1, or on thebicycle saddle, respectively, is pivoted or inclined, respectively, suchthat a driving experience as in a conventional bike is established.

Deviating therefrom, the third variant according to FIGS. 3 a and 3 bprovides that the first frame part 14 and the second frame part 15 areindeed mutually separated, or divided so as to be mutually pivotable,respectively, by two single joints 21, 22, as in the first variantaccording to FIGS. 1 a and 1 b , but the drive device 31 and the saddleare not assigned to the front, or first, frame part 14, but to thesecond, or rear, frame part 15. As a result, the driver when negotiatingcurves, or generally when the first frame part 14 is being pivoted inrelation to the second frame part 15, by way of his/her abdomen does notpivot to the position assumed in the curve, this potentially resultingin an unfamiliar driving experience.

In the vehicle 1 according to FIGS. 3 a and 3 b , a steeper profile ofthe pivot axis X moreover results from the positioning of the firstjoint 21 and the second joint 22. The second joint 22 is presentlydisposed on a transition between a top tube of the first frame part 14and a seat tube of the second frame part 15, and the first joint 21 isdisposed along the down tube, the latter being divided by the firstjoint 21 such that one part of the down tube is assigned to the firstframe part 14, and a second part of the down tube is assigned to thesecond frame part 15.

While a ball joint is provided as a first joint 21, and an elastomerelement is provided for the second joint 22, in FIGS. 3 a and 3 b , balljoints or elastomer elements may also be provided for both joints 21.

A steeper profile of the pivot axis X in the variants according to FIGS.1 and 2 can be achieved, for example, by displacing the joints 21, 22,or the joint 23, respectively, upward along the height axis H, or bydisplacing the entire superstructure of the second frame part 15 upwardalong the height axis H, the transport surface and the entire center ofgravity of the vehicle 1 being displaced as a result of the latter.

Illustrated in the plan view from above illustrated in FIG. 1 b or therespective plan views from above of the variants in FIGS. 1 b, 2 b and 3b , respectively, apart from the central position, resting position orneutral position of the first frame part 14, these being illustratedusing a solid line, are also by way of example deflected or pivotedpositions of the first frame part 14 in relation to the second framepart 15, this being illustrated using dashed lines. It becomes obvioushere that the contact point A is not or at least not significantlydisplaced, and the front or first frame part 14 can be tilted or rotatedor pivoted, respectively, in the transverse direction Q of the vehiclewithout the front or first frame part 14 changing the track of thesingle wheel 14 thereof in relation to the rear or second frame part 15.

In the case of a variation of the vehicle geometry, for example as aresult of a pressure loss in the single wheel 11 or a wheel change ofthe single wheel 11, it can arise that the contact point A of the singlewheel 11 is displaced such that the pivot axis X defined by the joints21, 22, 23 would no longer run through the contact point A, or exactlythrough the latter, respectively. It is therefore provided that thejoints 21, 22, 23 are adjustable, this however not being illustrated inthe figures. In the variant according to FIG. 1 , a position of thefirst joint 21 and/or of the second joint 22 is variable in thelongitudinal direction L and/or height direction H of the vehicle tothis end, such that the profile of the pivot axis X can be adjusted to anew contact point A by way of corresponding variation or displacement ofthe position. The same also applies to a single joint 23 according tothe embodiment of FIGS. 2 a and 2 b , wherein, as an alternative to anadjustability of the position, an adjustability of the angle may also beprovided here such that the angle of the joint 23 in relation to thefirst frame part 14 and/or the second frame part 15 in the variantaccording to FIGS. 2 a and 2 b is varied, and the profile of the pivotaxis X can be adjusted as a result.

In order to highlight the difference resulting from the embodimentaccording to the figures in comparison to the prior art, the singlewheel 11 of a vehicle 1 according to certain aspects herein isillustrated in FIG. 4 a , and a single wheel 41 of a vehicle known fromthe prior art is illustrated in FIG. 5 a . By tilting the first framepart 14 in relation to the second frame part 15, as is provided in thevariants according to FIGS. 1 a to 3 b , for example, the single wheel11 or the front wheel, respectively, is inclined about the contact pointA such that the latter acts as the fulcrum for the single wheel 11.Accordingly, the single wheel 11, when transitioning to the tiltedpositions 11′ thereof, is rotated about a fulcrum that lies in the planeof the ground B, this corresponding to the behavior of a normal wheel.

Deviating therefrom, FIG. 4 b shows the behavior of a vehicle of theprior art, which likewise has a divided frame, wherein the pivot axis ofthe front frame part of the latter in relation to the rear frame part ofthe latter does not run through the contact point A of the single wheel41 on the ground, but runs parallel to the ground, for example, suchthat a fulcrum D for the single wheel 41 results when the frame partsare pivoted. When the frame parts are tilted, the single wheel 41rotates to the tilted positions 41′ thereof, wherein the contact point Aas a result is displaced in the transverse direction Q such that thisresults in deviating contact points A′, or a displacement of the trackof the single wheel 41, respectively. The single wheel 41 remains incontact with the ground B by virtue of gravity. If the single wheel wereto be fixed about the rotation axis thereof, or about the fulcrum Dthereof, respectively, this, when rotating, would result in a heightoffset H in relation to the ground B.

FIGS. 5 a to 5 e by way of example show different drive concepts whichcan be used in the vehicle. The fundamental construction of the vehicle1, which is illustrated only in portions in FIGS. 5 a to 5 e , herecorresponds to the construction of a vehicle 1 according to the variantsof FIGS. 1 a to 3 b .

Provided in the drive concepts according to FIGS. 5 a and 5 b as thetorque transmission device is a prop shaft which extends from the firstframe part 14 into the second frame part 15, wherein the prop shaft runswithin the frame parts 14, 15 and, therefore, is not visible. The propshaft runs so as to be coaxial with the pivot axis X at least in theregion of the transition between the first frame part 14 and the secondframe part 15.

Provided besides a drive device 31 driven by muscular power in FIG. 5 a, or in the vehicle which is shown in portions in FIG. 5 a ,respectively, is a mid-mounted motor 33 configured as an electric motoras the second drive device, for example, wherein the two drive devices,by way of the prop shaft, transmit a torque generated by the latter fromthe region of the first frame part 14 to a differential 35 in the regionof the second frame part 15, the torque being distributed to the tworear wheels, or to the wheels 12, 13 of the pair of wheels,respectively, by the differential 35.

In the variant according to FIG. 5 b , two wheel hub motors 32 areprovided instead of a mid-mounted motor 33, wherein each of the wheels12, 13 of the pair of wheels is assigned one wheel hub motor 32.

Instead of a prop shaft, the embodiments according to FIGS. 5 c and 5 dprovide a chain drive, or a chain gear 34, respectively, as the torquetransmission device, wherein the chain of the chain drive 34 isconfigured to be twisted or torsioned, respectively, within apre-defined angular range about the pivot axis X, without being damaged.

Instead of a centrally disposed differential 35, the refinementaccording to FIG. 5 c , in each of the wheels 12, 13 of the pair ofwheels, provides a freewheeling hub 36, the latter conjointly actinglike a differential 35. In this variant, a mid-mounted motor 33 ismoreover provided.

Instead of a mid-mounted motor 33, the drive concept according to FIG. 5d provides for each of the wheels 12, 13 of the pair of wheels a wheelhub motor 32 assigned thereto, as well as a chain-driven differential37.

FIG. 5 e illustrates a further drive concept in which a torque from amuscle-power-operated drive device 31 which is presently embodied as abottom bracket bearing, or as a pedal mechanism, respectively, by meansof a chain of a chain gear 34 that is able to be torsioned about thepivot axis X, can be transmitted across the dividing plane of the frame,from the first frame part 14 to a second chain gear 34′ on the secondframe part 15. By way of a transverse drive shaft and a second chain,the second chain gear 34′ provides a transmission of torque to the rightwheel 12 of the wheels 12, 13 of the pair of wheels in the image planein which right wheel a wheel hub motor 32 is provided as a “master”. Thetwo wheels 12, 13 of the pair of wheels are not fastened by way of acommon axle or shaft, but are in each case fastened separately orindividually, respectively, on the luggage frame or on the second framepart 15, respectively. The left wheel 13 in the image plane likewisepossesses a wheel hub motor 32, which is however configured as a“slave”. Depending on a torque that is transmitted from the chain drives34, 34′ to the wheel hub motor 32, configured as the “master”, of theright wheel 12, and/or depending on a control that is adjustable by wayof an “accelerator” lever, for example, the wheel hub motor 32,configured as the “slave”, of the left wheel 13 can be actuated, and theleft wheel 13 be driven.

The invention is not limited in its embodiment to the preferredexemplary embodiments set out above. Rather, a number of variants areconceivable, which make use of the illustrated solution even withembodiments of fundamentally different types.

1-10. (canceled)
 11. A vehicle comprising: a multi-part frame; a singlewheel; and a pair of wheels having two mutually spaced-apart wheels;wherein the single wheel is connected to a first frame part of theframe; and wherein the two wheels of the pair of wheels are mounted on asecond frame part of the frame so as to be rotatable about a commonaxis, wherein the first frame part and the second frame part areconnected by at least one joint, wherein the first frame part and thesecond frame part are rotatable relative to one another about a pivotaxis defined by the at least one joint, and wherein the pivot axis runsthrough a contact point of the single wheel.
 12. The vehicle accordingto claim 11, wherein the single wheel is a front wheel, and wherein thefront wheel is coupled to a wheel fork, the wheel fork being connectedto the first frame part so that the front wheel is pivotable about asteering axis.
 13. The vehicle according to claim 11, wherein the firstframe part and the second frame part are connected by at least twojoints which are spaced apart on the pivot axis, wherein a first jointof the two joints is at least one of a ball joint, a radial bearing, andan elastomer element and wherein a second joint of the two joints is atleast one of a ball joint, a radial bearing, and an elastomer element.14. The vehicle according to claim 13, wherein a position of the firstjoint and/or of the second joint in relation to the first frame partand/or the second frame part is adjustable.
 15. The vehicle according toclaim 11, wherein the first frame part and the second frame part areconnected by exactly one joint formed by at least one radial bearing.16. The vehicle according to claim 11, further comprising at least oneof the following: a delimiting device which is configured to restrict arotatability of the first frame part in relation to the second framepart about the pivot axis; and a restoring device which is configured torotate the first frame part, from a position deflected in relation to apre-defined central position, back to the central position.
 17. Thevehicle according to claim 11, further comprising: at least onetorque-generating drive device, wherein the at least onetorque-generating device is coupled to at least one of the first framepart and the single wheel and is configured to transmit the torque tothe single wheel.
 18. The vehicle according to claim 11, furthercomprising: at least one torque-generating drive device that is disposedon the first frame part and, via a torque transmission device, isconfigured to transmit the torque to at least one of the wheels of thepair of wheels.
 19. The vehicle according to claim 18, wherein thetorque transmission device is a prop shaft which, at least in a regionof a dividing plane between the first frame part and the second framepart that is defined by the at least one joint, extends from the firstframe part to the second frame part so as to be coaxial with the pivotaxis.
 20. The vehicle according to preceding claim 18, wherein thetorque transmission device is a chain gear which has a chain and ofwhich the chain permits and compensates a twisting about the pivot axis.21. The vehicle according to claim 11, further comprising: at least onetorque-generating drive device that is disposed on the second frame partand, via a torque transmission device, is configured to transmit atorque to the single wheel.
 22. The vehicle according to claim 21,wherein the torque transmission device is a prop shaft which, at leastin the region of a dividing plane between the first frame part and thesecond frame part that is defined by the at least one joint, extendsfrom the first frame part to the second frame part so as to be coaxialwith the pivot axis.
 23. The vehicle according to claim 21, wherein thetorque transmission device is a chain gear which has a chain and ofwhich the chain permits and compensates a twisting about the pivot axis.24. The vehicle according to claim 11, further comprising: at least onetorque-generating drive device, wherein the at least onetorque-generating device is coupled to at least disposed on the secondframe part or directly on one of the wheels of the pair of wheels and isconfigured to transmit the torque to at least one of the wheels of thepair of wheels.
 25. A vehicle, comprising: a multi-part frame; a firstwheel; and a pair of wheels comprising a second wheel and a third wheel,the second wheel and the third wheel being coaxial and spaced apart,wherein the first wheel is connected to a first frame part of the frame,wherein the second wheel and the third wheel are both mounted on asecond frame part of the frame, wherein the first frame part and thesecond frame part are connected by at least one joint, wherein the firstframe part and the second frame part are rotatable relative to oneanother about a pivot axis defined by the at least one joint, andwherein the pivot axis runs through a contact point of the first wheel.26. The vehicle according to claim 25, wherein the first wheel is afront wheel, and wherein the front wheel is coupled to a wheel fork, thewheel fork being connected to the first frame part so that the frontwheel is pivotable about a steering axis.
 27. The vehicle according toclaim 11, wherein the first frame part and the second frame part reconnected by at least two joints which are spaced apart on the pivotaxis, wherein a first joint of the two joints is at least one of a balljoint, a radial bearing, and an elastomer element and wherein a secondjoint of the two joints is at least one of a ball joint, a radialbearing, and an elastomer element.
 28. The vehicle according to claim27, wherein a position of the first joint and/or of the second joint inrelation to the first frame part and/or the second frame part isadjustable.
 29. The vehicle according to claim 25, wherein the firstframe part and the second frame part are connected by exactly one jointformed by at least one radial bearing.
 30. The vehicle according toclaim 25, further comprising at least one of the following: a delimitingdevice which is configured to restrict a rotatability of the first framepart in relation to the second frame part about the pivot axis; and arestoring device which is configured to rotate the first frame part,from a position deflected in relation to a pre-defined central position,back to the central position.